Does growth hormone cause relapse of brain tumours?

Long-Term Safety of Growth Hormone Deficiency Treatment in Cancer and Sellar Tumors Adult Survivors: Is There a Role of GH Therapy on the Neoplastic Risk?

Experimental studies support the hypothesis that GH/IGF-1 status may influence neoplastic tissue growth. Epidemiological studies suggest a link between GH/IGF-1 status and cancer risk. However, several studies regarding GH replacement safety in childhood cancer survivors do not show a prevalence excess of de novo cancers, and several reports on children and adults treated with GH have not shown an increase in observed cancer risk in these patients. The aim of this review is to provide an at-a-glance overview and the state of the art of long-term effects of GH replacement on neoplastic risk in adults with growth hormone deficiency who have survived cancer and sellar tumors.

Noncontrast MRI Protocol for Selected Pediatric Pituitary Endocrinopathies: A Procedure with High Diagnostic Yield and Potential to Reduce Anesthesia and Gadolinium-Based Contrast Exposure

BACKGROUND AND PURPOSE

Although many pediatric neuroradiology practices empirically use noncontrast brain and pituitary MR imaging for evaluation of growth hormone deficiency, central precocious puberty, and short stature, there are currently insufficient published data to support this practice in an evidence-based fashion. Therefore, the use of contrast-enhanced MR imaging for all pediatric pituitary endocrinopathies remains widespread. We evaluated whether noncontrast MR imaging has adequate diagnostic yield for the evaluation of pediatric growth hormone deficiency, central precocious puberty, and short stature.

MATERIALS AND METHODS

Pituitary MR imaging studies obtained for growth hormone deficiency, central precocious puberty, or short stature in patients 0-18 years of age from 2010 to 2019 were analyzed. Separate blinded review of noncontrast images in cases with abnormalities on the original radiology report was performed by 2 subspecialty-trained pediatric neuroradiologists, with discrepancies resolved by consensus.

RESULTS

Of the 134/442 MR imaging studies obtained for growth hormone deficiency, central precocious puberty, or short stature with hypothalamic-pituitary region abnormalities, there was 70% concordance with the original reports on blinded review of noncontrast images. Twenty-two of 40 discrepancies were deemed unrelated to the indication, and 9 cases originally interpreted as possible microadenoma were read as having normal findings on blinded review. Only 9 of 40 discrepancies required contrast for further characterization.

CONCLUSIONS

In our study, most relevant radiologic findings in patients with growth hormone deficiency, central precocious puberty, and short stature were detectable without contrast, providing evidence that contrast can be avoided in routine MR imaging evaluation of these indications. We propose a "rapid noncontrast pituitary" MR imaging protocol for pediatric patients presenting with growth hormone deficiency, central precocious puberty, or short stature, which may increase efficiency and decrease contrast and anesthesia exposure.

Safety of growth hormone (GH) treatment in GH deficient children and adults treated for cancer and non-malignant intracranial tumors-a review of research and clinical practice

Individuals surviving cancer and brain tumors may experience growth hormone (GH) deficiency as a result of tumor growth, surgical resection and/or radiotherapy involving the hypothalamic-pituitary region. Given the pro-mitogenic and anti-apoptotic properties of GH and insulin-like growth factor-I, the safety of GH replacement in this population has raised hypothetical safety concerns that have been debated for decades. Data from multicenter studies with extended follow-up have generally not found significant associations between GH replacement and cancer recurrence or mortality from cancer among childhood cancer survivors. Potential associations with secondary neoplasms, especially solid tumors, have been reported, although this risk appears to decline with longer follow-up. Data from survivors of pediatric or adult cancers who are treated with GH during adulthood are scarce, and the risk versus benefit profile of GH replacement of this population remains unclear. Studies pertaining to the safety of GH replacement in individuals treated for nonmalignant brain tumors, including craniopharyngioma and non-functioning pituitary adenoma, have generally been reassuring with regards to the risk of tumor recurrence. The present review offers a summary of the most current medical literature regarding GH treatment of patients who have survived cancer and brain tumors, with the emphasis on areas where active research is required and where consensus on clinical practice is lacking.

Long-Term Endocrine and Metabolic Consequences of Cancer Treatment: A Systematic Review

The number of patients surviving ≥5 years after initial cancer diagnosis has significantly increased during the last decades due to considerable improvements in the treatment of many cancer entities. A negative consequence of this is that the emergence of long-term sequelae and endocrine disorders account for a high proportion of these. These late effects can occur decades after cancer treatment and affect up to 50% of childhood cancer survivors. Multiple predisposing factors for endocrine late effects have been identified, including radiation, sex, and age at the time of diagnosis. A systematic literature search has been conducted using the PubMed database to offer a detailed overview of the spectrum of late endocrine disorders following oncological treatment. Most data are based on late effects of treatment in former childhood cancer patients for whom specific guidelines and recommendations already exist, whereas current knowledge concerning late effects in adult-onset cancer survivors is much less clear. Endocrine sequelae of cancer therapy include functional alterations in hypothalamic-pituitary, thyroid, parathyroid, adrenal, and gonadal regulation as well as bone and metabolic complications. Surgery, radiotherapy, chemotherapy, and immunotherapy all contribute to these sequelae. Following irradiation, endocrine organs such as the thyroid are also at risk for subsequent malignancies. Although diagnosis and management of functional and neoplastic long-term consequences of cancer therapy are comparable to other causes of endocrine disorders, cancer survivors need individually structured follow-up care in specialized surveillance centers to improve care for this rapidly growing group of patients.

Growth Hormone's Links to Cancer

Several components of the GH axis are involved in tumor progression, and GH-induced intracellular signaling has been strongly associated with breast cancer susceptibility in genome-wide association studies. In the general population, high IGF-I levels and low IGF-binding protein-3 levels within the normal range are associated with the development of common malignancies, and components of the GH-IGF signaling system exhibit correlations with clinical, histopathological, and therapeutic parameters in cancer patients. Despite promising findings in preclinical studies, anticancer therapies targeting the GH-IGF signaling system have led to disappointing results in clinical trials. There is substantial evidence for some degree of protection against tumor development in several animal models and in patients with genetic defects associated with GH deficiency or resistance. In contrast, the link between GH excess and cancer risk in acromegaly patients is much less clear, and cancer screening in acromegaly has been a highly controversial issue. Recent studies have shown that increased life expectancy in acromegaly patients who attain normal GH and IGF-I levels is associated with more deaths due to age-related cancers. Replacement GH therapy in GH deficiency hypopituitary adults and short children has been shown to be safe when no other risk factors for malignancy are present. Nevertheless, the use of GH in cancer survivors and in short children with RASopathies, chromosomal breakage syndromes, or DNA-repair disorders should be carefully evaluated owing to an increased risk of recurrence, primary cancer, or second neoplasia in these individuals.

Occurrence of neoplasms in individuals with congenital, severe GH deficiency from the Itabaianinha kindred

Growth hormone (GH) and the insulin-like growth factor I (IGF-I) have cell proliferative and differentiation properties. Whether these hormones have a role in mutagenesis is unknown. Nevertheless, severe IGF-I deficiency seems to confer protection against the development of neoplasms. Here, we report five cases of adult patients with severe and congenital isolated GH deficiency (IGHD) due to the c.57+1G>A mutation in the GHRH receptor gene, who developed tumors. Four GH-naïve subjects presented skin tumors: a 42-year-old man with a fibroepithelial polyp, a 53-year-old woman and two men (59 and 56 years old) with epidermoid skin cancers. One of these died from it after three surgeries and radiotherapy. The fifth patient was a 25-year-old woman, who had intermittently received GH replacement therapy (GHRT) from age 11 to 18, who developed an ependymoma extending from the fourth ventricle to the end of the thoracic spine. She underwent three surgical procedures, without obvious evidence of tumor recurrence during the six years follow up. These observations suggest that severe IGHD does not protect completely from development of tumors.

Pediatric Craniopharyngiomas: A Primer for the Skull Base Surgeon

Pediatric craniopharyngioma is a rare sellar-region epithelial tumor that, in spite of its typically benign pathology, has the potential to be clinically devastating, and presents a host of formidable management challenges for the skull base surgeon. Strategies in craniopharyngioma care have been the cause of considerable controversy, with respect to both philosophical and technical issues. Key questions remain unresolved, and include optimizing extent-of-resection goals; the ideal radiation modality and its role as an alternative, adjuvant, or salvage treatment; appropriate indications for expanded endoscopic endonasal surgery as an alternative to transcranial microsurgery; risks and benefits of skull base techniques in a pediatric population; benefits of and indications for intracavitary therapies; and the preferred management of common treatment complications. Correspondingly, we sought to review the preceding basic science and clinical outcomes literature on pediatric craniopharyngioma, so as to synthesize overarching recommendations, highlight major points of evidence and their conflicts, and assemble a general algorithm for skull base surgeons to use in tailoring treatment plans to the individual patient, tumor, and clinical course. In general terms, we concluded that safe, maximal, hypothalamic-sparing resection provides very good tumor control while minimizing severe deficits. Endoscopic endonasal, intraventricular, and transcranial skull base technique all have clear roles in the armamentarium, alongside standard craniotomies; these roles frequently overlap, and may be further optimized by using the approaches in adaptive combinations. Where aggressive subtotal resection is achieved, patients should be closely followed, with radiation initiated at the time of progression or recurrence-ideally via proton beam therapy, although three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, and stereotactic radiosurgery are very appropriate in a range of circumstances, governed by access, patient age, disease architecture, and character of the recurrence. Perhaps most importantly, outcomes appear to be optimized by consolidated, multidisciplinary care. As such, we recommend treatment in highly experienced centers wherever possible, and emphasize the importance of longitudinal follow-up-particularly given the high incidence of recurrences and complications in a benign disease that effects a young patient population at risk of severe morbidity from hypothalamic or pituitary injury in childhood.

Physiologic Growth Hormone-Replacement Therapy and Craniopharyngioma Recurrence in Pediatric Patients: A Meta-Analysis

OBJECTIVE

A systematic review and meta-analysis were conducted to examine the effect of growth hormone-replacement therapy (GHRT) on the recurrence of craniopharyngioma in children.

METHODS

PubMed, Embase, and Cochrane databases were searched through April 2017 for studies that evaluated the effect of GHRT on the recurrence of pediatric craniopharyngioma. Pooled effect estimates were calculated with fixed- and random-effects models.

RESULTS

Ten studies (n = 3487 patients) met all inclusion criteria, including 2 retrospective cohorts and 8 case series. Overall, 3436 pediatric patients were treated with GHRT after surgery and 51 were not. Using the fixed effect model, we found that the overall craniopharyngioma recurrence rate was lower among children who were treated by GHRT (10.9%; 95% confidence interval 9.80%-12.1%; I² = 89.1%; P for heterogeneity <0.01; n = 10 groups) compared with those who were not (35.2%; 95% confidence interval 23.1%-49.6%; I² = 61.7%; P for heterogeneity = 0.11; n = 3); the P value comparing the 2 groups was <0.01. Among patients who were treated with GHRT, subgroup analysis revealed that there was a greater prevalence of craniopharyngioma recurrence among studies conducted outside the United States (P < 0.01), single-center studies (P < 0.01), lower impact factor studies (P = 0.03), or studies with a lower quality rating (P = 0.01). Using the random-effects model, we found that the results were not materially different except for when stratifying by GHRT, impact factor, or study quality; this led to nonsignificant differences. Both Begg's rank correlation test (P = 0.7) and Egger's linear regression test (P = 0.06) indicated no publication bias.

CONCLUSIONS

This meta-analysis demonstrated a lower recurrence rate of craniopharyngioma among children treated with GHRT than those who were not.

Physiological growth hormone replacement and rate of recurrence of craniopharyngioma: the Genentech National Cooperative Growth Study

OBJECTIVE The object of this study was to establish recurrence rates in patients with craniopharyngioma postoperatively treated with recombinant human growth hormone (rhGH) as a basis for determining the risk of rhGH therapy in the development of recurrent tumor. METHODS The study included 739 pediatric patients with craniopharyngioma who were naïve to GH upon entering the Genentech National Cooperative Growth Study (NCGS) for treatment. Reoperation for tumor recurrence was documented as an adverse event. Cox proportional-hazards regression models were developed for time to recurrence, using age as the outcome and enrollment date as the predictor. Patients without recurrence were treated as censored. Multivariate logistic regression was used to examine the incidence of recurrence with adjustment for the amount of time at risk. RESULTS Fifty recurrences in these 739 surgically treated patients were recorded. The overall craniopharyngioma recurrence rate in the NCGS was 6.8%, with a median follow-up time of 4.3 years (range 0.7-6.4 years.). Age at the time of study enrollment was statistically significant according to both Cox (p = 0.0032) and logistic (p < 0.001) models, with patients under 9 years of age more likely to suffer recurrence (30 patients [11.8%], 0.025 recurrences/yr of observation, p = 0.0097) than those ages 9-13 years (17 patients [6.0%], 0.17 recurrences/yr of observation) and children older than 13 years (3 patients [1.5%], 0.005 recurrences/yr of observation). CONCLUSIONS Physiological doses of GH do not appear to increase the recurrence rate of craniopharyngioma after surgery in children, but long-term follow-up of GH-treated patients is required to establish a true natural history in the GH treatment era.

Growth hormone therapy and risk of recurrence/progression in intracranial tumors: a meta-analysis

Growth hormone deficiency is common in intracranial tumors, which is usually treated with surgery and radiotherapy. A number of previous studies have investigated the relationship between the growth hormone replacement therapy (GHRT) and risk of tumor recurrence/progression; however, the evidence remains controversial. We conducted a meta-analysis of published studies to estimate the potential relation between GHRT and intracranial tumors recurrence/progression. Three comprehensive databases, PUBMED, EMBASE, and Cochrane Library, were researched with no limitations, covering all published studies till the end of July, 2014. Reference lists from identified studies were also screened for additional database. The summary relative risks (RR) and 95% confidence intervals (CI) were calculated by fixed-effects models for estimation. Fifteen eligible studies, involving more than 2232 cases and 3606 controls, were included in our meta-analysis. The results indicated that intracranial tumors recurrence/progression was not associated with GHRT (RR 0.48, 95% CI 0.39-0.56), and for children, the pooled RR was 0.44 and 95% CI was 0.34-0.54. In subgroup analysis, risks of recurrence/progression were decreased for craniopharyngioma, medulloblastoma, astrocytoma, glioma, but not for pituitary adenomas, and non-functioning pituitary adenoma (NFPA), ependymoma. Results from our analysis indicate that GHRT decreases the risk of recurrence/progression in children with intracranial tumors, craniopharyngioma, medulloblastoma, astrocytoma, or glioma. However, GHRT for pituitary adenomas, NFPA, and ependymoma was not associated with the recurrence/progression of the tumors. GH replacement seems safe from the aspect of risk of tumor progression.

Growth hormone treatment and risk of malignancy

Growth hormone (GH) treatment has been increasingly widely used for children with GH deficiencies as the survival rate of pediatric patients with malignancies has increased. Both GH and insulin-like growth factor-I have mitogenic and antiapoptotic activity, prompting concern that GH treatment may be associated with tumor development. In this review, the authors examined the relationship between GH treatment and cancer risk in terms of de novo malignancy, recurrence, and secondary neoplasm. Although the results from numerous studies were not entirely consistent, this review of various clinical and epidemiological studies demonstrated that there is no clear evidence of a causal relationship between GH treatment and tumor development. Nonetheless, a small number of studies reported that childhood cancer survivors who receive GH treatment have a small increased risk of developing de novo cancer and secondary malignant neoplasm. Therefore, regular follow-ups and careful examination for development of cancer should be required in children who receive GH treatment. Continued surveillance for an extended period is essential for monitoring long-term safety.

Safety of growth hormone treatment in patients previously treated for cancer

This review provides an overview of the safety of growth hormone replacement therapy in individuals previously treated for cancer. The review focuses on the risk of disease recurrence and second neoplasm occurrence with special attention to data on childhood cancer survivors.

Growth hormone therapy and the risk of tumor recurrence after brain tumor treatment in children

To assess the effect of human growth hormone (hGH) therapy and other factors on tumor recurrence after treatment of pediatric brain tumors (BTs), we retrospectively analyzed data from 108 craniopharyngioma, medulloblastoma, and ependymoma patients. Risk factors were identified using multifactorial univariate regression analysis. Recurrences occurred in 41 and second malignant neoplasms in 4 patients. There were significant correlations for completeness of tumor removal and recurrence-free survival (RFS). 13/44 hGH-treated and 28/59 non-hGH-treated children relapsed. This difference was found only for medulloblastomas and accounted for by higher rates of incomplete tumor removal in non-hGH patients. Craniopharyngioma recurrence correlated only with RFS. Malignant BT recurrence correlated with completeness of tumor removal, chemotherapy, and RFS. 4 children developed SMNs, 3/4 after hGH therapy. Our regression model yielded accurate within-sample prediction of recurrence for 90% of the study population. We conclude that hGH therapy after treatment of pediatric BTs does not increase tumor recurrence risk.

Acromegaly, growth hormone and cancer risk

Acromegaly is an endocrine disorder characterized by sustained hypersecretion of growth hormone (GH) with concomitant elevation of insulin-like growth factor I (IGF-I) associated with premature mortality from cardiopulmonary diseases and certain malignancies. In particular, there is a two-fold increased risk of developing colorectal cancer. Possible mechanisms underlying this association include elevated levels of circulating GH and IGF-I, but several other plausible processes may be relevant. In a parallel literature, there has been debate whether GH replacement therapy is associated with increased cancer risk in three scenarios: (1) tumour recurrence in children with previously treated cancer; (2) second neoplasms (SNs) in survivors of childhood cancer treated with GH; and (3) de-novo cancer in non-cancer patients treated with GH. The general evidence suggests no increased risk in scenario 1. Through a maze of complex study designs, there is inconclusive evidence of a very modest increase in cancer risk in treated GH-deficiency patients in scenarios 2 and 3, but it is likely that the cumulative risk equates to that of the general population. This emphasizes the need for patient selection balanced against the known morbidity of untreated GH deficiency.

Growth hormone secretion and response to growth hormone therapy after treatment for brain tumour

Children irradiated for brain tumours constitute an increasing group of patients who will require GH therapy. High-dose cranial irradiation is necessary for cure, but inevitably causes GH deficiency within a few years. In 19 patients investigated between 2 and 9 years after irradiation, the spontaneous 24-hour GH secretion was markedly reduced. The secretory pattern indicated loss of regulating hypothalamic hormones. After exogenous GHRH was administered, the pituitary was able to respond with a prompt GH release, showing that pituitary function was unaffected. Ten prepubertal children growing at 3.8 +/- 0.3 cm/year were treated with GH, 0.1 IU/kg/day s.c. Their growth rate increased to 8.2 +/- 0.4 cm in the first year. An increased growth rate was also maintained in the second year.

Growth hormone treatment and cancer risk

Increasing numbers of children receive growth hormone (GH) to treat a range of growth disorders, including those rendered GH deficient (GHD) by tumors or their treatment. Young persons with persistent growth hormone deficiency (GHD) and adults with severe GHD are also eligible to receive GH treatment. As in vitro and in vivo studies and epidemiologic observations provide some evidence that the GH--insulin like growth factor-I (IGF-I) axis is associated with tumorigenesis, it is important to assess, in practice, the incidence of tumors related to GH treatment. Reassuringly, surveillance studies in large cohorts of children and in smaller cohorts of adults indicate that GH is not associated with an increased incidence of tumor occurrence or recurrence. Nevertheless, all children who have received GH, in particular cancer survivors and those receiving GH in adulthood, should be in surveillance programs to assess whether an increased rate od late-onset and rare tumours may occur.

Pathophysiology of radiation-induced growth hormone deficiency: efficacy and safety of GH replacement

Radiation-induced growth hormone deficiency (GHD) is primarily due to hypothalamic damage. GH secretion by the pituitary may be affected either secondary to some degree of quantitative deprivation of hypothalamic input or, if the radiation dose is high enough, by direct pituitary damage. As a consequence, the neurosecretory profile of GH secretion in an irradiated patient remains pulsatile and qualitatively intact. The frequency of pulse generation is unaffected, but the amplitude of the GH pulses is markedly reduced. Over the last 25 years, the final heights achieved by children receiving GH replacement for radiation-induced GHD have improved; these improvements are attributable to refinements in GH dosing schedules, increased use of GnRH analogues for radiation-induced precocious puberty, and a reduced time interval between completion of irradiation and initiation of GH therapy. When retested at the completion of growth, 80-90% of these teenagers are likely to prove severely GH deficient and, therefore, will potentially benefit from GH replacement in adult life. Such long-term GH treatment in patients treated previously for a brain tumor means that critical and continuous surveillance must be devoted to the risk of tumor recurrence and the possibility of second neoplasms.

Adult growth hormone replacement therapy and neuroimaging surveillance in brain tumour survivors

OBJECTIVE

Systematic collections of neuroimaging data are nonexistent in brain tumour survivors treated with adult growth hormone replacement therapy (AGHRT). We present our surveillance data.

DESIGN

In 1993, our unit implemented a policy of performing brain scans on every brain tumour survivor before starting AGHRT, with repeat neuroimaging at least once after 12-18 months' treatment. Reports for baseline scans and most recent scans were analysed for this retrospective study.

PATIENTS

All brain tumour survivors who received AGHRT (60 patients) were included in the analysis.

MEASUREMENTS

Evidence and extent of residual tumour, tumour progression, tumour recurrence, and secondary neoplasms (SN) on baseline scan and latest follow-up scan.

RESULTS

All patients had baseline scans performed. Follow-up scans were available in 41/45 (91%) patients who received AGHRT for more than 1 year (mean duration +/- SD of GHRT was 6.7 +/- 3.6 years). Sixteen patients had residual tumours, and SNs (all meningiomas) were demonstrated in three patients on baseline scans. Appearances remained stable in 34 (83%) patients during follow-up (extending to 17.4 +/- 8.3 years after tumour diagnosis). Of the 16 residual primary tumours, an incurable ependymoma continued to grow, and one meningioma progressed slightly in size over 7.7 years. Follow-up scans also revealed continued growth of the SNs detected at baseline, and five additional meningiomas (two in patients with a previous SN, confirming an excess risk in this subgroup, P = 0.02). All SNs occurred on average 22.8 (range 17-37) years after radiotherapy.

CONCLUSIONS

Our data do not suggest an increased rate of recurrence or progression of childhood brain tumours during AGHRT. Nonetheless, vigilance and long-term surveillance are needed in these patients in order to detect and monitor SNs, in particular in patients with a previous history of a SN. We endorse a proactive neuroimaging policy, preferably as part of a larger, controlled trial in the future.

Cancer Risk Following Growth Hormone Use in Childhood

The therapeutic use of growth hormone (GH) has caused concern, as it is anabolic and mitogenic, and its effector hormone, insulin-like growth factor (IGF)-I is anti-apoptotic. As both hormones can cause proliferation of normal and malignant cells, the possibility that GH therapy may induce cancer, increase the risk of tumour recurrence in those previously treated for a malignancy, or increase the risk of cancer in those with a predisposition, has resulted in concerns over its use. There are theoretical and epidemiological reasons that suggest GH and IGF-I may be important in tumour formation and proliferation. Malignant tumours have been induced in animals exposed to supraphysiological doses of GH, whereas hypophysectomy appears to protect animals from carcinogen-induced neoplasms. In vitro, proliferation and transformation of normal haemopoetic and leukaemic cells occurs with supraphysiological doses of GH, but not with physiological levels. IGF, IGF binding proteins (IGFBP) and IGFBP proteases influence the proliferation of cancer cells in vitro; however, GH is probably not involved in this process. Epidemiological studies have suggested an association between levels of IGF-I and cancer, and an inverse relationship between IGFBP-3 and cancer; however, these associations have been inconsistent. A number of studies have been undertaken to determine the risk of the development of cancer in children treated with GH, either de novo, or the recurrence of cancer in those previously treated for a malignancy. Despite early concerns following a report of a cluster of cases of leukaemia in recipients of GH, there appears to be no increased risk for the development of leukaemia in those treated with GH unless there is an underlying predisposition. Even in children with a primary diagnosis of cancer, subsequent GH use does not appear to increase the risk of tumour recurrence. However, a recent follow-up of pituitary GH recipients has suggested an increase in colorectal cancer. In addition, follow-up of oncology patients has suggested an increase in second neoplasms in those who also received GH therapy. These studies emphasise the importance of continued surveillance both internationally with established databases and also nationally through single-centre studies.

Influence of growth hormone therapy on pituitary and lumbar spine astrocytomas. A clinical observation

We report on a male patient with an inactive pituitary and lumbar astrocytoma. He presented with panhypopituitarism at the age of 16 and received growth hormone replacement therapy for one year. During this period the pituitary mass increased substantially and showed subsequently a consistent shrinkage once treatment was stopped. The lumbar lesion stayed stable for the whole period of observation. The presumable rGH related change of the pituitary astrocytoma underlines the importance of careful follow-up of children with growth hormone deficiency secondary to treatment for brain tumors. Substitution therapy with rGH requires further and longer studies before it can be recommended with absolute reassurance in children with subtotal resection of a pituitary astrocytoma.

Growth hormone treatment of children with brain tumors and risk of tumor recurrence

GH is increasingly used for treatment of children and adults. It is mitogenic, however, and there is therefore concern about its safety, especially when used to treat cancer patients who have become GH deficient after cranial radiotherapy. We followed 180 children with brain tumors attending three large hospitals in the United Kingdom and treated with GH during 1965-1996, and 891 children with brain tumors at these hospitals who received radiotherapy but not GH. Thirty-five first recurrences occurred in the GH-treated children and 434 in the untreated children. The relative risk of first recurrence in GH-treated compared with untreated patients, adjusted for potentially confounding prognostic variables, was decreased (0. 6; 95% confidence interval, 0.4-0.9) as was the relative risk of mortality (0.5; 95% confidence interval, 0.3-0.8). There was no significant trend in relative risk of recurrence with cumulative time for which GH treatment had been given or with time elapsed since this treatment started. The relative risk of mortality increased significantly with time since first GH treatment. The results, based on much larger numbers than previous studies, suggest that GH does not increase the risk of recurrence of childhood brain tumors, although the rising trend in mortality relative risks with longer follow-up indicates the need for continued surveillance.

Safety issues in children and adolescents during growth hormone therapy--a review

The action of growth hormone (GH) via its receptor involves many organ systems and metabolic pathways. These diverse actions are reviewed in this paper in the context that they may represent unwanted side-effects of GH therapy for growth promotion. The monitoring of GH therapy in large multicentre international databases has demonstrated a low frequency of adverse events. Tumour recurrence or new malignancy are not increased. Headaches, especially in the first few months of therapy, require close evaluation as benign intracranial hypertension is found infrequently, especially in children with GH deficiency and chronic renal failure (CRF). Children at risk for slipped capital femoral epiphysis and scoliosis require close monitoring during therapy. Decreased insulin sensitivity that is dose-dependent is observed during GH therapy. Glucose homeostasis, however, is not affected, but a recent report of increased incidence of Type 2 diabetes mellitus in children undergoing GH therapy requires prospective surveillance.

Endocrine dysfunctions in patients treated for brain tumors: incidence and guidelines for management

Endocrine alterations are frequently found in patients undergoing treatment for CNS tumors. Careful follow-up aimed at the early detection of recurrences, with life-long monitor of hypothalamus-pituitary (HP) function, will also reveal any endocrine dysfunctions; indeed, their appropriate diagnosis and treatment may determine a significant improvement in the quality of life of these patients.

Growth failure after treatment of pediatric brain tumors

OBJECTIVES

Primary brain tumors are the most common solid tumors that occur in childhood. With improved management of these tumors, there are more survivors with long-term sequelae of radiation and chemotherapy including growth failure. The aim of this study was to assess growth prospectively in children with nonpituitary-related primary brain tumors.

METHODS

Forty-one children 3.1 to 13.8 years of age diagnosed consecutively between 1989 and 1992 with a primary nonpituitary-related brain tumor were studied.

RESULTS

Of 34 prepubertal children, 14 (41%) were diagnosed as having growth hormone (GH) deficiency. All 14 children were treated with cranial irradiation. During the first year from completion of brain tumor therapy, the annual height velocity of those children confirmed subsequently as being GH-deficient was 3.06 +/- 1.19 cm compared with 5.29 +/- 2.21 cm for those who were not GH-deficient. During the second year, the annual height velocity was 3.29 +/- 1.14 cm per year for the GH-deficient group compared with 5.48 +/- 1.24 cm per year for the non-GH-deficient group. All children with GH deficiency received cranial irradiation and chemotherapy. Two of 34 children developed precocious puberty. Primary hypothyroidism was diagnosed in 6 of 41 children (12%).

CONCLUSION

We conclude that GH deficiency and primary hypothyroidism are common after cranial irradiation and chemotherapy for nonpituitary-related brain tumors. Linear growth appears to reflect GH status accurately in children with brain tumors. Precise auxologic evaluation is simple and noninvasive and may reflect more accurately GH status than provocative GH testing. These findings reflect the need for prospective growth monitoring of children with nonpituitary-related brain tumors treated with cranial irradiation and chemotherapy. Early diagnosis of GH deficiency facilitates early initiation of GH therapy and optimization of final height.

Deterrents to the successful clinical use of growth factors that enhance protein anabolism

Participants in competitive sports have demonstrated that the use of growth factors and other anabolic agents enhance human performance, yet physicians are slow to adopt this approach in patients who have a disease-related decrease in strength and activity. Growth factors should be thought of as the next major step forward in providing more efficient and effective nutritional support to catabolic or wasted patients. The obstacles to the use of these agents include: the lack of convincing clinical studies; concerns with safety; anabolic effects and the patient's nutritional status; interaction with diet and route of nutrient administration; the training of health professionals to administer growth factors; and cost. The benefits from these agents should be directly translated into improved patient outcome. To achieve this goal, a uniquely educated group of investigators, working with sophisticated representatives from the pharmaceutical industry, must emerge to construct appropriate protocols and determine desirable endpoints to evaluate the true societal benefits of these agents.

Relapse of intracranial germinoma 23 years postirradiation in a patient given growth hormone replacement

There is no clear evidence that growth hormone replacement therapy for treatment-related growth hormone deficiency in patients with childhood intracranial malignancies has a role in tumour relapse or second malignancy. A 16-year-old girl with an intracranial germinoma was treated with local radiotherapy and subsequently received growth hormone replacement therapy as an adult. Three years after starting growth hormone therapy, 23 years after her radiotherapy treatment, the patient's tumour recurred. Surveillance requirements for patients receiving growth hormone in this setting are discussed.

Combined cabergoline and recombinant human growth hormone treatment of an adolescent with a macroprolactinoma causing GH deficiency

The rare macroprolactinomas seen in childhood frequently cause delayed puberty and GH deficiency. We report the combined use of cabergoline and recombinant human GH (rhGH) therapy in a male adolescent with macroprolactinoma and GH deficiency. Computed tomography and magnetic resonance imaging of the hypothalamic-pituitary region showed a macroadenoma with extrasellar extension. Neither bromocriptine nor dihydroergocryptine therapy was successful in decreasing serum PRL levels. On cabergoline treatment normal serum PRL levels were achieved within 3 months along with a marked shrinkage of the adenoma but growth rate did not increase nor did puberty start. The addition of exogenous rhGH therapy improved the growth rate, but complete pubertal development was obtained only after the administration of exogenous gonadotropins. During the combined treatment no expansion of the macroadenoma was observed. In conclusion, the combined therapy with cabergoline and rhGH seems to be safe and highly effective. Nevertheless, it warrants careful monitoring and on-going evaluation.

Expansion and shrinkage of central nervous system tumor coinciding with human growth hormone therapy: case report

OBJECTIVE AND IMPORTANCE

The influence of human growth hormone (hGH) therapy on the recurrence rates of childhood central nervous system tumors is controversial. Because growth hormone has the ability to increase cell proliferation, it is recommended that hGH therapy wait until central nervous system lesions are inactive and antitumor therapy complete, usually 1 to 2 years.

CLINICAL PRESENTATION

We report the enlargement and decrease in size of a hypothalamic pilocytic astrocytoma in a 12-year-old boy after two trials of hGH. Partial resection and radiation of the tumor were performed at 3 years of age, with no change noted over the next 9 years. His height was less than the 5th centile with midparental height at the 90th to 95th centiles. Growth velocity was 3.3 cm/yr. Bone age was normal and there were no signs of puberty. There was no GH response to clonidine and L-dopa testing.

INTERVENTION

Volume measurements were performed on gadolinium enhanced tumor images. Growth rate increased to 11.7 cm and the tumor volume increased 230% over the 12 months of hGH therapy. Significant tumor shrinkage (42%) and growth deceleration occurred within the 3 month interval of stopping hGH. Tumor volume again increased (134%) and decreased (22%) after restarting and then stopping hGH. No evidence of tumor necrosis or alteration in ventricular size was found. The patient was asymptomatic.

CONCLUSION

These observations indicate that tumor size change is associated with the metabolic response to hGH therapy. It is unclear whether the volume increase represents altered blood-brain or selective blood-tumor barrier permeability, growth factor receptors, and/or tumor cell growth.

Bifrontal basal interhemispheric approach to craniopharyngioma resection with or without division of the anterior communicating artery

The authors describe the use of a bifrontal basal interhemispheric approach with or without division of the anterior communicating artery (ACoA) for removal of large craniopharyngiomas. This approach is a more basal modification of the anterior interhemispheric approach; allowing preservation of most bridging veins. Since 1988, 22 patients underwent operations using this approach to achieve total or near-total excision of large craniopharyngiomas. Division of the ACoA was performed in 11 of 17 patients with retrochiasmatic tumors with no early or late complications related to division of the artery. There were no operative mortalities. Visual improvement (59%) and preservation of the pituitary stalk (64%) were achieved in a high percentage of patients. Preservation of the pituitary stalk correlated well with postoperative pituitary function. The bifrontal basal interhemispheric approach allowed a bilateral, wider operative field with better orientation and views of important neural structures and perforating arteries without requiring combination with other approaches. When the ACoA limited operative exposure, the artery could be divided safely. The authors discuss indications for, and advantages of, the bifrontal basal interhemispheric approach with or without division of the ACoA in the removal of large craniopharyngiomas.

Brain tumor recurrence in children treated with growth hormone: the National Cooperative Growth Study experience

As of October 1993 the National Cooperative Growth Study included 1262 children with brain tumor who were treated with growth hormone. The type of brain tumor was specified in 947 (75%) of these children. The most common types were glioma, medulloblastoma, and craniopharyngioma, accounting for 91.3% of all those for which type was specified. Brain tumor recurred in 83 (6.6%) of the 1262 children over a total of 6115 patient-years at risk. The frequencies of tumor recurrence in children with low-grade glioma (18.1%), medulloblastoma (7.2%), and craniopharyngioma (6.4%) are lower than those in published reports of tumor recurrence in the general pediatric population with the same types of tumors. The analysis cannot conclusively show that no increased risk of tumor recurrence exists, however, because of the potential incompleteness of data reporting in the National Cooperative Growth Study. Nevertheless the findings are reassuring that children with the more common types of brain tumor who are treated with growth hormone do not seem to be at excessive risk for tumor recurrence.

The safety and effectiveness of human growth hormone using pharmacological dosing

Human growth hormone in currently recommended dosage is effective in many short children, irrespective of their endogenous growth-hormone status. This suggests that present dosing is pharmacological rather than physiological. As for any drug, issues of safety should be of paramount concern. Reassuring short-term data with pharmacological dosing or long-term data with replacement dosing cannot guarantee the ultimate safety of this form of therapy. The risk of future malignancy should be of particular concern. Poorly growing children without classic (severe) growth-hormone deficiency constitute an increasing proportion of children treated with human growth hormone. There are no satisfactory criteria for the diagnosis of neurosecretory growth-hormone dysfunction. The closer to puberty these children are treated, the less likely it is that there will be benefits in terms of increased final height. Recommendations as to a 'safety first' approach to growth-hormone treatment are given. A multicentre controlled trial is urgently needed to establish the benefits of treating children with neurosecretory growth hormone dysfunction.

Is brain tumor recurrence increased following growth hormone treatment?

Growth hormone (GH) deficiency and resultant growth failure are common sequelae in children with brain tumors, often requiring treatment with GH. Several studies over the past decade have addressed the concern as to whether GH treatment in these children results in an increased rate of tumor recurrence. The findings in general are reassuring, although there are analytic problems with all the studies. This present article reviews the previously published studies, as well as the experience at the Children's Hospital of Philadelphia.

Late leukemic relapse 10 years from diagnosis in a child on recombinant human growth hormone

A 12 year-old girl developed a late relapse of acute lymphoblastic leukaemia (ALL) 10 years from first presentation. Initial chemotherapy included vincristine, methotrexate, prednisolone, and L-asparaginase with cranial radiotherapy (18 Gy) for central nervous system prophylaxis. Documented growth failure led to recombinant human growth hormone (rhGH) replacement therapy being instituted in May 1989, 6 years from end of therapy and 2 years prior to relapse. Three independent experiments demonstrated no increased cell proliferation in vitro when the patient's thawed cryopreserved fresh leukemic cells were incubated with rhGH. However, a pre-T ALL cell line (PER-255) consistently demonstrated enhanced proliferation when incubated with rhGH (132.1 +/- 13.4%, P < 0.01). Growth hormone has been associated with an increased incidence of leukemia and may be implicated in the late relapse of this child. The use of growth hormone in children with a past history of ALL needs to be examined critically in the light of the potential risk of inducing leukemic relapse.

Conventional and nonconventional uses of growth hormone

Although GH has been available as a therapeutic agent for the GH-deficient child for more than 30 years, the conditions of its use have yet to be optimized. The availability of biosynthetic material has provided researchers with the opportunity to develop the protocols necessary to begin to finally answer the most fundamental questions pertaining to dose, frequency, and duration of treatment. It has also permitted the initiation of prospective trials in a large number of conditions that result in childhood short stature, with the expectation that some or many of them will be treated effectively and safely. Finally, it has opened the door to an entire spectrum of potentially new uses of GH and other growth factors for so-called nonconventional indications. That these have implications that range from the short-term rapid healing of a burn graft site, to the more efficient induction of ovulation, to the long-term preservation of lean body mass has excited the interest of investigators in many fields of medicine and physiology. Thus, the recent progress reported in this paper is really the beginning of the new research that will take place with GH and growth factors.

Growth hormone therapy in the elderly: implications for the aging brain

Growth hormone (GH) secretion declines during normal aging, resulting in lower serum insulin-like growth factor (IGF)-I levels. It has been proposed that many of the catabolic changes seen in normal aging, including osteoporosis and muscle atrophy, are in part caused by the decreased action of the GH-IGF-I axis. In addition, patients with GH deficiency have increased overall cardiovascular mortality. Several investigators have initiated GH treatment for elderly patients with relative hyposomatotropinemia. Initial reports suggest that GH can increase muscle mass, improve exercise tolerance, increase REM sleep and cause an enhanced sense of well-being. The basis for neuropsychiatric changes during GH therapy may be due to a direct CNS action of GH itself, to the increased IGF-I secretion which GH elicits, or to enhanced functioning of peripheral organ systems. Long-term studies will determine whether GH or IGF-I can exert a neurotrophic action in the aging brain.

Irradiation-induced growth failure

GH deficiency, skeletal disproportion and early or precocious puberty may complicate irradiation to the head or axial skeleton in childhood. Certain cohorts of children are at particular risk, including those irradiated for brain tumours and various haematological malignancies. Both GH deficiency and impaired spinal growth may result in short stature, whereas the occurrence of early puberty in association with GH deficiency reduces the time available for GH therapy. The age of the child at irradiation is critical in that, in younger children, the central nervous system is more radiosensitive, the severity of the subsequent skeletal disproportion is greatest and the onset of puberty earliest. It is the very young craniospinally-irradiated child who is most at risk of extreme short stature.

[Late effects on the hypothalamo-pituitary function after the treatment of parasellar tumors]

Long term follow-up of patients submitted to treatment of parasellar tumours region is important for the detection of late therapeutic complications. In this study the authors conducted an evaluation of six patients with craniopharyngioma, one with germinoma, one with meningioma, and one epidermoid cyst. All above tumours were localized at parasellar region. Six out of nine patients had been treated both by surgery and by radiotherapy and the other three surgically only, on an average 3.8 +/- 3.2 years before this observation was carried out. Five patients were female with their ages average 24.3 +/- 18.8 years old. Evaluation consisted: in the first place, an intravenous infusion of thyrotropin-releasing hormone (TRH, 200 micrograms), gonadotropin-releasing hormone (GnRH, 100 micrograms), and insulin tolerance test (0.1 IU/Kg, regular insulin); and secondly, in measurements of pituitary hormones secretion at different time points--0, 20, 40, 60 and 80 minutes. We found both diminished response of growth hormone and cortisol in all the patients. Seven out of nine patients did not have adequate response to follicle-stimulating hormone. Three out of nine responded unsatisfactory to luteinizing hormone. Four out of nine showed inadequate responses to prolactin as well as, two out of eight to thyrotropin. We concluded that: (a) growth hormone and cortisol deficiency are the most frequent finding in these patients; (b) post-radiotherapy lesions can be located in the hypothalamus or pituitary, or even in both; (c) hypophysial and hypothalamic cells sensitivity to irradiation is different, according to their respective hormones; and (d) it is necessary a frequent endocrinologic follow-up of patients to detect late hormonal deficiencies.

Growth hormone deficiency following radiation therapy of primary brain tumors in children

The medical records of 123 patients treated for brain tumors at Children's Hospital and Medical Center, Seattle, Washington, between 1985 and 1987 were reviewed. The endocrinological complications of radiation therapy and the effectiveness of growth hormone (GH) replacement therapy were assessed. These were the first 2 years after synthetic GH became available. The disease pathology was confirmed at craniotomy or biopsy in 108 patients. Ninety-five children completed radiation therapy and 65 of these were alive at the time of review; these 65 children represent the study population. The most common tumor types were medulloblastoma, craniopharyngioma, and ependymoma. Endocrine evaluation was initiated with changes in the patients' growth velocity. Patient workup included skeletal x-ray films for determination of bone and analysis of thyroxin, thyroid-stimulating hormone, and somatomedin-C levels. Following 1-dopa and clonidine stimulation, provocative studies of GH levels were performed. Growth hormone failure and short stature were observed in 26 children, most commonly in the 2nd year after tumor treatment. Eight patients with GH failure were also hypothyroid. Hormone replacement therapy was initiated with recombinant GH, 0.05 mg/kg/day, and all children so treated showed an increase in height, with eight patients experiencing catch-up growth. There were no complications of therapy or tumor recurrence. Studies of baseline bone age and somatomedin-C levels on completion of radiation therapy are recommended. Comprehensive endocrine studies should follow changes in the patients' growth velocity. With early GH replacement, catch-up growth is possible and normal adult heights may be achieved.

Mortality, neoplasia, and Creutzfeldt-Jakob disease in patients treated with human pituitary growth hormone in the United Kingdom

OBJECTIVE

To determine the cause of death and incidence of neoplasia in patients treated with human pituitary growth hormone.

DESIGN

A long term cohort study established to receive details of death certification and tumour registrations through the Office of Population Censuses and Surveys and NHS central register.

PATIENTS

All patients (1246 male, 662 female) treated for short stature with pituitary growth hormone under the Medical Research Council working party and health services human growth hormone committee.

MAIN OUTCOME MEASURES

Death or development of neoplasia.

RESULTS

110 patients died (68 male, 42 female; aged 0.9-57 years) from 1972 to 1990. Fifty three death were from neoplasia responsible for growth hormone deficiency (27 craniopharyngioma, 24 other intracranial tumour, two leukaemia); two from histiocytosis X; and 13 from pituitary insufficiency. Six patients died of Creutzfeldt-Jakob disease, six of other neurological disorders, and eight of acute infection. Other deaths were apparently unrelated to growth hormone deficiency or its treatment. Seventeen tumours (in 16 patients) were identified during or after growth hormone treatment. Four were in patients with previous intracranial neoplasia and two were after cranial irradiation. Thirteen were intracranial, the others being Hodgkin's lymphoma, osteosarcoma, carcinoma of colon, and basal cell carcinoma.

CONCLUSIONS

Recurrence or progression of intracranial tumours and potentially avoidable metabolic consequences of hypopituitarism were the main causes of death. Growth hormone treatment probably did not contribute to new tumour development. Creutzfeldt-Jakob disease after pituitary growth hormone treatment continues to occur in the United Kingdom. This cohort must remain under long term review.

Dose dependency of time of onset of radiation-induced growth hormone deficiency

Growth hormone (GH) secretion during insulin-induced hypoglycemia was assessed on 133 occasions in 82 survivors of childhood malignant disease. All had received cranial irradiation with a dose range to the hypothalamic-pituitary axis of 27 to 47.5 Gy (estimated by a schedule of 16 fractions over 3 weeks) and had been tested on one or more occasions between 0.2 and 18.9 years after treatment. Results of one third of the GH tests were defined as normal (GH peak response, greater than 15 mU/L) within the first 5 years, in comparison with 16% after 5 years. Stepwise multiple linear regression analysis showed that dose (p = 0.007) and time from irradiation (p = 0.03), but not age at therapy, had a significant influence on peak GH responses. The late incidence of GH deficiency was similar over the whole dose range (4 of 26 GH test results normal for less than 30 Gy and 4 of 25 normal for greater than or equal to 30 Gy after 5 years), but the speed of onset over the first years was dependent on dose. We conclude that the requirement for GH replacement therapy and the timing of its introduction will be influenced by the dose of irradiation received by the hypothalamic-pituitary axis.

Growth and growth hormone secretion in children following treatment of brain tumours with radiotherapy

We have studied the growth of 144 children after treatment of brain tumours distant from the hypothalamo-pituitary axis. All had cranial irradiation and 87 spinal irradiation. In 56 patients observed without intervention for 3 years, height SDS in the cranial (CR) group (n = 20) declined from 0.02 to -0.44 and in the craniospinal (CS) group (n = 36) from -0.28 to -1.11. Failure of spinal growth had a marked effect in the CS group. The onset of puberty was slightly but not significantly advanced; median ages at onset of puberty were 10.3 years in girls and 12.1 years in boys. Of the total group 86.4% had clinical and biochemical evidence of growth hormone insufficiency. Fifty-two children, 33 (28 CS; 5 CR) of whom were prepubertal, received biosynthetic human growth hormone, in a dose of 15 mU/m2/week by daily injection for a period of one year. Height velocity SDS increased significantly in both groups from -2.74 to +1.90 (CS) and from -1.0 to +4.26 (CR). Spinal response to GH treatment was restricted in the craniospinal group.

Response to growth hormone treatment and final height after cranial or craniospinal irradiation

Growth hormone (GH) deficiency (GHD) induced by cranial irradiation has become a frequent indication of hGH substitutive therapy. This study analyses the growth response to hGH therapy and the factors involved in the decrease in growth velocity observed after cranial irradiation. One hundred children (61 boys and 39 girls) given cranial radiation for pathology distant from the hypothalamo-pituitary area were studied. Fifty-six of them received hGH therapy for GHD resulting in decreased growth velocity. The initial annual height gain in the cranial-irradiated group was comparable to that of patients treated for idiopathic GHD; additional spinal irradiation significantly reduced the growth response. Twenty-eight hGH-treated patients reached final heights which were compared to those of 2 untreated irradiated groups, one with GHD (n = 27) and the other with normal GH secretion (n = 17). The height SD score changes observed in hGH therapy were +0.3 in the cranial (n = 10) and -1.2 SD in the craniospinal (n = 18) groups. GH deficiency had contributed to a mean height loss of 1 SD and spinal irradiation to a loss of 1.4 SD. The small effect of hGH therapy on final height is probably linked to the small bone age retardation at onset of hGH therapy and to the fact that irradiated children entered puberty at a younger age in terms of chronological age (10.6 +/- 0.3 yr in girls and 11.0 +/- 0.3 yr in boys) and bone age (9.6 +/- 0.4 yr in girls and 12.6 +/- 0.3 in boys) than the idiopathic GHD patients. These data suggest that the results of hGH therapy in irradiated children might be improved with higher and more fractionated hGH doses and, in some patients, by delaying puberty using luteinizing hormone releasing hormone analogs.

Management of growth failure in the treatment of malignant disease

Growth failure due to endocrine dysfunction as a result of treatment for malignant disease is becoming increasingly common. It may occur after cranial or craniospinal irradiation given in the treatment of acute lymphoblastic leukemia and brain tumors, and is often coupled with early or precocious puberty. It also occurs after neck and gonadal radiation and is particularly severe after total body irradiation where multiple endocrine deficiencies frequently occur. Failure to appreciate its occurrence or failure to institute therapy early enough may lead to short stature in adult life. Accurate and regular monitoring of standing and sitting height, bone age, and endocrine data should be undertaken by the oncologist in close collaboration with an endocrinologist, to ensure appropriate management of the patient.